Two-line element set: Difference between revisions

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m v2.05 - Fix errors for CW project (Unbalanced quotes in ref name or illegal character or empty name.)
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The internal format used three 80-column punch cards. Each card started with a card number, 1, 2 or 3, and ended with the letter "G". For this reason, the system was often known as the "G-card format". In addition to the orbital elements, the G-card included various flags like the launching country and orbit type (geostationary, etc.), calculated values like the [[perigee]] altitude and visual magnitude, and a 38-character comments field.
 
The transmission format is essentially a cut-down version of the G-card format to make, removing any data that is not subject to change on a regular basis, or data that can be calculated using other values. For instance, the perigee altitude from the G-card is not included as this can be calculated from the other elements. What remains is the set of data needed to update the original G-card data as additional measurements are made. The data is fit into 69 columns and does not include a trailing character. TLEs are simply the transmission format data rendered as ASCII text.
 
An example TLE for the [[International Space Station]]: